milan_ns

I think it is just bad luck. I had to go through two used mirrors until I found a functional one. With used one costing £70 and the new one costing £530, solution is really obvious :-)

Ouch! Ah well, you live and learn My replacement mirror came from VW Golf mk7. It came with plastic bits attached, but I couldn't use them as those were different from mine (Golf's plastic cover are different from Octavia's), so I had to replace the plastic cover from my old mirror. Worst case scenario could simply buy those plastic bits from Skoda dealer. Those should cost a few pounds at most.

No prob. When reinstalling the mirror, it's easier to first snap the mirror back into place, then connect the cable, then replace the plastic cable cover (top plastic part that you have just removed, in the photo). Also, your new mirror will likely arrive without plastic covers (those are in fact sold under different part numbers), so you'll have to remove the entire plastic cover (both plastic parts) from your old mirror and place it on the new mirror.

Sensor that is still attached to the windscreen is, as far as I know, daylight sensor (for auto low beam; i.e. for when you set headlights to 'auto'). If auto low beam works, no need to replace it. High Beam Assist sensor on the other hand is part of the mirror assembly (bit that you have removed and are holding on your hand in the photo). So if you have problems with HBA system, this is the part you need to replace. BTW HBA sensor is that camera looking part on the front of the mirror.

Mine looks just like that.

My setup looks very similar to the one on the video and I can remove and re-install my mirror by following the video instructions. If yours is different, then am afraid I can't help.

Try like to...

Looks good. Yep, go for it! That is how I have done it - and I'm not really a car mechanic

Correct... note down the "Long coding" code. New part will likely have different code, that you'd need to modify to match the one you just posted.

While this may work for office computers, it will likely not work for your HBA. If it says it is dead, it is quite dead. However, you will not need to re-code it if you unplug it and plug it back again. HBA has a memory chip that remembers settings even when unplugged - otherwise it would forget the settings each time you turn off the car. Interesting fact: Coding is specific to a particular make and model (e.g. 2017 Octavia with bi-xenons will have different coding from 2017 Octavia with halogen headlights). If you by some magic find a mirror from the same specification car as yours, you may not even need to code it.

You can do it all yourself - if you have OBD11 Pro. No tools required. It takes like 15 minutes. Steps: connect the ODB11 Pro read the "long code" from the existing faulty part (it is under "20 High Beam Assistance" sub-system) and note it down remove the faulty mirror remove the plastic that connects mirror to the lining (cable cover) twist the entire mirror assembly anti-clockwise and it should snap off the windscreen (don't pull, it should come off on its own) disconnect the cable install the new mirror connect the cable place the mirror onto the windscreen mount, twist it clockwise until it clicks put back the plastic cable cover connect the OBD11 Pro update the long code to match the the previously noted code Done!

I would imagine it is the same part number. I got one of my mirrors from Ireland - and they also drive on the left. You could check though. Just have a look at the number stamped on the bottom of your current mirror, if you still have it.

Part number is "5G0857511D SMA". I got one on ebay (faulty as it turned out) and another one from Allegro.pl website. On Allegro you can find quite a few of these mirrors: https://goo.gl/t5pNYb Website is in polish only, but I managed with the help of Google Translate Keep in mind that you will most likely need to code the replacement mirror to fit your car before it starts working.

Solved!!

I have resolved the problem! Firstly I got a new (used) mirror, which, as it turned out, also had a faulty HBA sensor. Then on my second attempt I got myself another one, again used, for 90 EUR - new one is like 475 EUR Using OBDEleven Pro I updated the long code on the replacement to match my old faulty mirror (replacement was coded for a VW Golf) and viola - my HBA works again!!

Did you manage to solve this? Thanks!

Tried to replace the sensor (entire mirror), but the problem persists (OBDeleven finds the new part, but shows the same error). Anybody knows where does the control module that controls the HBA live? How does it look like :D?

ODBEleven found this: Date: 2018-12-24 16:20 VIN: TMBJJ7NE9E0098273 Car: Skoda Octavia Year: 2014 Body type: Estate Engine: CKFC 110 kW (150 HP) 2.0 l Mileage: 80051 KM --------------------------------------------------------------- 20 High Beam Assistance System description: FLA Software number: 5G0857511D Software version: 0002 Hardware number: 5G0857511 Hardware version: H04 ODX name: EV_HighBeamAssisAU37X ODX version: 001009 Long coding: 02018F6B76765D525220343E01 Trouble codes: B200047 - Ctrl. module faulty static I'm new to the terminology and I'm unclear as to what the 'Ctrl. module' is Shall I assume that the sensor (one built into the rearview mirror) died (and needs to be replaced) or...? Thanks

I couldn't find the photos in your thread, however I figured out how to remove the mirror myself :-) In mean time, my ODBEleven package arrived, so I now have the error code relating to light assist: "B200047 - Ctrl. module faulty" I guess I will open another thread since in relation to the error code

Thanks for the advice people! I think I'll order myself the OBDEleven package and scan the car before going to the dealers - or buying a new mirror

I have not "checked the coding". I'm new to the whole 'connect-your-car-to-a-computer' thing. I have just ordered bluetooth OBD2 dongle to have a play with it. Would I be able to "check the coding" with it? Or do I need to get a full blown VCDS cable and the app? My thinking is: It worked fine up to few days ago. I have not made any changes to the car since few months ago. Ergo, it's probably the case of sensor going bad. I tried reseting the car settings (within the car infotainment system), but it made no difference. So my next step is to replace the sensor - or the mirror, since sensor is integrated. I found a used one for £100.

As per the subject, how does one remove the rearview mirror on Octavia mk3 (dimmable mirror, with light assist)? Car started reporting "Fault: Light assist" and I want to replace the light assist sensor - which happens to be integrated into the mirror. I assume I could just replace the entire mirror and the whole thing should just work? Would there be any coding required? Thanks :)